Department of Applied Biological Sciences, Jordan University of Science and Technology, Irbid, Jordan.
Pol J Microbiol. 2009;58(4):339-45.
The purpose of this study was to determine the influence of growth conditions and medium composition on the production ofchitinase by Streptomyces sp. (strain S242). Production of chitinase by strain S242 was detected on colloidal chitin agar (CCA) medium after 8 days of incubation at 28 degrees C resulting in a clear zone 10 mm around the colony. Chitinase activity was assayed as the amount of N-acetylglucosamine released in micromol/ml/min using the dinitrosalicylic acid assay method. The crude enzyme had maximum activity (0.162 U ml/l) after 4 days of incubation at pH 7 and 30 degrees C when the broth medium was supplemented with 1.6% of colloidal chitin. However, enzyme activity was strongly decreased at 40 degrees C and extreme acidic and alkaline pH values. SDS-PAGE and zymogram analysis revealed six distinctive bands that range from 39 to 97 kDa with chitinolytic activity. The findings of this investigation create a possibility for the use of the organism in the commercial production of chitinase. In addition, it can be a source of DNA for cloning the chitinase gene(s) to generate phytopathogen resistant transgenic plants.
本研究旨在确定生长条件和培养基组成对链霉菌（S242 株）产生几丁质酶的影响。在 28°C 下孵育 8 天后，在胶体几丁质琼脂（CCA）培养基上检测到 S242 菌株产生的几丁质酶，导致菌落周围出现 10 毫米的清晰区域。用二硝基水杨酸法测定 N-乙酰氨基葡萄糖的释放量，以微摩尔/毫升/分钟为单位测定几丁质酶活性。粗酶在 pH7 和 30°C 下培养 4 天时活性最高（0.162 U ml/l），当培养基中补充 1.6%胶体几丁质时。然而，在 40°C 和极端酸性和碱性 pH 值下，酶活性会强烈下降。SDS-PAGE 和酶谱分析显示，有 6 条特征带，分子量范围从 39 到 97 kDa，具有几丁质酶活性。这项研究的结果为该生物在几丁质酶的商业生产中的应用提供了可能性。此外，它可以作为克隆几丁质酶基因以产生抗植物病原体的转基因植物的 DNA 来源。
